NP229 rebuild or any T-case really.

[eaglescout526]

So I am getting the 229 rebuild going, I got a good chunk of the way last night. Today I decided to test the shifting, which is what made me open up, investigate and rebuild the t-case in the first place. And its improved but its still not shifting easily with hi-n-lo and 2wd-4wd is still being stubborn but it seems like it will shift fine with pressure on the mode fork. Now I removed the main shaft to test this as I wasnt getting much cooperation shifting with the shaft in. Is there anything I can do to? Grease maybe? Maybe I am missing something or I need to make sure all surfaces are smooth? I also have a part that I have no idea where it goes, but it could also not go with the t-case at all. 

 

I am open to suggestions as I have never rebuilt a t-case and a 229 is not the best case to start with hahaha but I enjoy a challenge. Its a somple case really, I think its because theres more levers and forks than a normal case and even the 242. 

 

here's the part:

 

here's where I think it goes:

 

But I tried to put it there, it worked until it locked the shift rod in place and had to take it apart to get it out. Does anyone recognize this part?

[87MJTIM]

That looks like a “lock-out” detent pin. It’s to prevent one shift rail from moving while another rail is in a certain gear. For example, some transfer cases won’t allow 2wd-low.  The 231 only has 2h, 4h, and 4l.

 

 I don’t know anything about a 229. It’s probably a good idea to put it back in place. 

[eaglescout526]

3 hours ago, 87MJTIM said:

I don’t know anything about a 229. It’s probably a good idea to put it back in place. 

That’s the problem haha. I don’t remember where it went. I did put it back last night, when I shifted the main rail, it locked me out of shifting it back at all. Even when I moved the case so gravity would work against the pin it still locked the rail in place which also lead me to think I need grease or something in all these moving parts before it gets filled with fluid to make sure I have proper operation. 
I’d hate to put this case in and have shifting issues right away. 

[EUREKA]

I have rebuilt three 231's using novak adapters kits, one was a sye. I don't recall that part in the 231. It has been about 5 years since the last one I did so my memory isn't sharp but I recall the detent in the 231 being spherical. I will say that these cases are intended to change mode when the vehicle is rolling slowly in neutral. They can be sometimes be stubborn to shift modes unless you rotate the input shaft. I think I have a 242 and a 249, maybe also a 231 in my shed.

 

I can open one and look inside if you get really stuck here. But it might be after Thanksgiving.

[schardein]

I don’t see that part in the exploded diagram. 55-58 looks like a detent ball for the shift rail. But I don’t see an interlock. The diagrams for the Dana 20 and 300 in the same manual show the interlocks. 

[eaglescout526]

I saw the exploded diagram as well and never saw the ball. And I know this thing couldnt have spawned out of thin air in my garage, The 229 could probably live without it but I will try to get it back together this evening and see what I find.

 

34 minutes ago, EUREKA said:

I think I have a 242 and a 249, maybe also a 231 in my shed.

 

I can open one and look inside if you get really stuck here. But it might be after Thanksgiving.

In no rush,  not like I am gonna get it installed tonight or tomorrow or soon haha. I do have the hard part done which is the needle bearings. 

[Eagle_SX4]

If I remember correctly that is the detent ball to prevent you from putting the transfer case into 2-low. With some modifications you can remove it to get 2-low. When I rebuilt mine I had a factory rebuild guide. I will look for it when I get home tonight.

[Eagle_SX4]

I found a link to the manual and lots of NP229 docs.

 

https://oljeep.com/edge_tcase.html

 

This website has lots of useful info.

[Eagle_SX4]

Just read through the manual and that "pill" isn't mentioned in there but I think there is a slot in-between the two shift rails and it goes in there.

[eaglescout526]

30 minutes ago, Eagle_SX4 said:

I found a link to the manual and lots of NP229 docs.

 

https://oljeep.com/edge_tcase.html

 

This website has lots of useful info.

I have this tab open believe it or not. Strikes me as the same as my XJ FSM. But yeah both don’t mention that pill. I’m gonna put it in and put some assembly grease on everything that moves so I can make sure this case will go in every position. That being said, should I run it without the pill and get my self 2 lo? Sounds like it wouldn’t be a bad option to have if it’s as easy as not putting that pill back in. 

[Eagle_SX4]

I think that you would also need to add a notch in the range sector (no. 83 on the diagram). Or modify it in some manner.

[eaglescout526]

3 hours ago, Eagle_SX4 said:

I think that you would also need to add a notch in the range sector (no. 83 on the diagram). Or modify it in some manner.

Interesting. I’ll just stick the pill in and I found it in the diagram. On the web link you provided, it’s no55. I speculate this as the ball detent thing that attaches to the spring is one piece and the “ball” they refer to is the pill shaped thing. 

[watchamakalit]

I've never been into a np transfer case, but I have homebrew twinsticked a couple of d300's years ago. Part of the twinstick job was removing a very similar pill to allow independent movement of the shift rails. This allowed for control of the front and rear out put separate from each other. That said I'm not sure it will work the same for the np case due to a single shift point and not 2 separate shift rails.

I would be very apprehensive about leaving that pill out. The homebrew twin sticks had an issue with the concept that would allow an inept user to put the case in high and low gear range for the opposite axles. This resulted in rapid tcase disassembly, usually at unwanted moments.

[eaglescout526]

Funny enough the 229 would allow for twin sticks already. The mode select rail is just controlled by a vacuum actuator vs yourself. So if you eliminated that actuator and set up a shifting system for the mode, you could have a twin stick 229. 

[coheed]

I have a 228 in the shed that I could potentially take apart. The only difference is the center "diff". I can also say that it will refuse to shift out of the vehicle unless I'm spinning the input. It would also be after Thanksgiving before I could tear it apart

[eaglescout526]

Yeah it uses a traditional diff vs the viscous coupling in the 229 but otherwise the same tcase. I know both the 228/9 have to have some motion to change but I even tried rotating and even lining up the gears and couldn’t get the mode to change out of the Jeep. 

[eaglescout526]

I’m gonna kinda use this as a documentation thread as well now seeing how even SJ guys just throw them the wayside. Fun fact, if you cut off or remove the viscous coupling from the differential assembly, you will have an NP228. Neat to know. 
 

Any how, it looks like a good chunk of my shifting issues stemmed from the annulus gear. No I didn’t put it in wrong but apparently doing it how the FSM says to do it and it skip a step and just put the whole gear assembly in is pretty important unbeknownst to me. I thought hey, I could just put the whole gear assembly in without taking it apart. Well taking it apart helped line up the range rod to where I shouldn’t have any more issues and it seems like  2wd-4wd is working as it should now that I have the main shaft and mode rail back in. This tcase is a tricky one. But I should be able to press on now. 
 

 

Now a new question, I have the system sentry along with NOS probe sensors for the fluid level. Where should I put a hole for the sensor or should I attempt to do such?